While running for U.S. Senate last year, Chris Vance was one of the few Republican candidates in the nation to publicly break with the party’s presidential nominee, Donald Trump. He is a supporter of the American Civil Liberties Union. (Dean Rutz/The Seattle Times)

Chris Vance was drinking his morning coffee and reading the text of President Trump’s first executive order banning visitors from some Muslim-majority countries when he decided he had to take action.

So the prominent Republican from Auburn, Wash., who said the order was “antithetical to what I believed as an American,” grabbed his laptop and did what thousands of Americans have done to register their outrage toward the president: He joined the American Civil Liberties Union, pledging to donate money every month to the organization.

Donating to the ACLU has become an act of political defiance in the Trump era as the group has positioned itself as a high-profile and aggressive opponent of the president’s agenda.

Since the election, after which the group famously challenged Trump — saying that it would “see you in court” — membership has nearly tripled to 1.2 million, and the group has collected more than $80 million in online donations alone. It is adding scores of attorneys and investigators, and faced with a new surge of volunteers, it has started a grass-roots arm to mobilize them to lobby on state and local matters.

It is a new and potentially risky position for one of the nation’s best-known nonprofit organizations, which is liberal-leaning but has built a reputation of crossing ideological lines on issues such as gun rights and political spending and has famously represented some of those most detested in society, including suspected terrorists and neo-Nazis.

Some conservatives say the organization has shifted away from principles of free speech and religious liberties over the years in favor of popular liberal causes such as abortion and gay rights, and they say the ACLU favors atheists and other religions over Christians.

Jay Sekulow, chief counsel for the American Center for Law and Justice who has advocated for the rights of Christians, offered the example of the entry ban. A federal judge blocked the original executive order, leading the administration to revise it last week, citing the need to protect national security. But the ACLU and others remain opposed because they view it as targeting Muslims.

“There was nothing the president could do that would have satisfied the ACLU except not issue it,” Sekulow said. “That’s where they are ideologically.”

Vance said he took a lot of heat for his decision to join such an openly anti-Trump organization, with conservatives on social media and talk radio denouncing him as disloyal and a “RINO” — a Republican In Name Only. Vance said he is unperturbed by the criticism.

“I’m, like, Mr. Republican in this state,” said Vance, a former state representative and GOP chairman who ran unsuccessfully for the U.S. Senate last year. “I have always thought the ACLU was very consistent. They stand up for the Bill of Rights.”

Vance was a prominent critic of Trump during the election and did not cast a ballot for president. On Tuesday, he said that Trump’s new entry ban is “dramatically better” than the previous one, which he felt more openly targeted Muslims. But he said he continues to oppose it.

The original version was blocked by a federal judge, whose decision was upheld by a federal appeals panel, but Trump has revised it in a way that his administration says passes legal muster.

ACLU officials acknowledge they have never taken such an oppositional stance against a president. However, they argue that they have built capital in their nearly 100-year history by challenging every president, including many with whom they largely agree.

During President Barack Obama’s time in office, the organization repeatedly took him to task over his use of drones to attack suspected terrorists and his reliance on mass surveillance. Decades earlier, the ACLU led the legal fight against the creation of Japanese internment camps under Franklin D. Roosevelt, a liberal icon.

The ACLU has characterized Trump as a unique threat to American ideals, calling him a “one-man constitutional crisis.” The organization has filed more than a dozen legal actions against his policies in his first month in office — mostly targeting the entry ban — and says that it has found no common ground with him on his proposals.

“We think lawsuits can help crystallize policy debates for the public to engage,” said Anthony Romero, executive director of the ACLU. “Litigation can also . . . gum up the machinery of the Trump administration. If we can rob them of momentum, we can keep them from doing greater harm or damage.”

Rock-star status

The ACLU has tried to blunt the impact of Trump’s actions in a number of ways: It increased its legal assistance in heavily Latino neighborhoods after immigration authorities stepped up deportations last month. It pledged to move forward on a transgender student’s lawsuit after the administration revoked guidance calling for schools to allow students to use the bathroom of their choice. It submitted a Freedom of Information Act request for the administration’s plans to issue an executive order expanding the rights of people of faith to opt out of activities or laws that infringe on their religious beliefs — a proposal the group criticized as anti-gay. It has pledged to aggressively defend Planned Parenthood if Trump and congressional Republicans follow through on their promise to defund it. And it has called for a special prosecutor to investigate Trump’s campaign ties with Russia.

The group’s stance has earned it rock-star status in liberal circles, with fancy restaurants and even yoga studios holding ACLU fundraisers. At the Academy Awards, some actors wore blue ACLU pins. At a comedy club fundraiser in Chicago in January, the crowd at one point chanted the name of the local affiliate’s communications director, Ed Yohnka.

“Here I am — I’m a white, middle-aged guy with a bald head who wears a suit and tie every day. They’re chanting, ‘Ed! Ed! Ed!’ ” Yohnka said, referring to his appearance at a nighttime event attended by hip urbanites. The event, he said, was “really affirming of the work that we do.”

The ACLU’s position on religious liberties has been a particular source of controversy.

In 1993, the organization was among the broad cross-section of politicians and groups that supported the passage of the federal Religious Freedom Restoration Act. The legislation came after the U.S. Supreme Court upheld the decision of the state of Oregon to deny unemployment benefits to two Native Americans after they were fired for testing positive for the use of drugs used during a religious ceremony.

Congress tried three years later to pass another version of the bill after it was struck down by the Supreme Court. But the ACLU and others withheld support, in part because it was opposed by the burgeoning gay rights movement, said John Inazu, a law professor at Washington University in St. Louis.

In recent years, the ACLU has been a vociferous opponent of state attempts to pass religious freedom bills viewed as anti-gay.

Some critics have noted the group’s shift on protests outside abortion clinics. In 2000, the ACLU sided with conservative religious protesters in Colorado challenging restrictions outside of the clinics. In 2014, it sided with the government and against protesters in a similar case in Massachusetts.

For religious conservatives, “the most plausible explanation would be a shift toward reproductive rights and away from religious freedom and free-speech concerns,” Inazu said.

Charles C. Haynes, founding director of the Religious Freedom Center at the Newseum Institute, said the ACLU has mostly remained true to its mission. At a time when the president is facing vocal opposition, it follows that the organization would be popular, he said.

But there have been times that it has hemorrhaged members, he said, such as when it defended the rights of neo-Nazis to march in Skokie, Ill., in the 1970s. In 2009, it sued a Florida school district on behalf of students barred from wearing T-shirts that read, “Islam is of the Devil.”

“What I would say is if the ACLU defends anything you don’t like, you should just suck it up because, remember, tomorrow the ACLU will defend something you do like,” Haynes said.